The ease of use and the manageability of each module, such as environment variables or collections.

I am using postman from last 3 years and this is the best for Callouts, to check the APIs of any aplication to change the data of the particular apps. Like I am working as a Salesforce Developer, So It helps to integrate any software with Salesforce to check which Outh that app using to run the apis smoothlt also we can change the data using POST callout. In Postman there are several pre defined API which you can use to intergrate something or to make callouts.

It supports http methods like GET,POST,PUT,DELETE.It works with restful API and soap AI and websocket API's.It allows creation of enviornments with variables like Base URL's, API keys to simplify testing in different set ups (Dev,QA,Production). It can organize API requests into collections for better workflow management and the collection can include API calls, scripts and test cases. It can automate tasks like setting headers, autentication tokens or extracting data from the output response.It enbales to share the collections,test cases within the teams.It allows creating mock servers to simulate API responses for testing before the backend isfully developed.